1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2  * contributor license agreements.  See the NOTICE file distributed with
3  * this work for additional information regarding copyright ownership.
4  * The ASF licenses this file to You under the Apache License, Version 2.0
5  * (the "License"); you may not use this file except in compliance with
6  * the License.  You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "apr_arch_thread_rwlock.h"
18 #include "apr_private.h"
19 
20 #if APR_HAS_THREADS
21 
22 #ifdef HAVE_PTHREAD_RWLOCKS
23 
24 /* The rwlock must be initialized but not locked by any thread when
25  * cleanup is called. */
thread_rwlock_cleanup(void * data)26 static apr_status_t thread_rwlock_cleanup(void *data)
27 {
28     apr_thread_rwlock_t *rwlock = (apr_thread_rwlock_t *)data;
29     apr_status_t stat;
30 
31     stat = pthread_rwlock_destroy(&rwlock->rwlock);
32 #ifdef PTHREAD_SETS_ERRNO
33     if (stat) {
34         stat = errno;
35     }
36 #endif
37     return stat;
38 }
39 
apr_thread_rwlock_create(apr_thread_rwlock_t ** rwlock,apr_pool_t * pool)40 APR_DECLARE(apr_status_t) apr_thread_rwlock_create(apr_thread_rwlock_t **rwlock,
41                                                    apr_pool_t *pool)
42 {
43     apr_thread_rwlock_t *new_rwlock;
44     apr_status_t stat;
45 
46     new_rwlock = apr_palloc(pool, sizeof(apr_thread_rwlock_t));
47     new_rwlock->pool = pool;
48 
49     if ((stat = pthread_rwlock_init(&new_rwlock->rwlock, NULL))) {
50 #ifdef PTHREAD_SETS_ERRNO
51         stat = errno;
52 #endif
53         return stat;
54     }
55 
56     apr_pool_cleanup_register(new_rwlock->pool,
57                               (void *)new_rwlock, thread_rwlock_cleanup,
58                               apr_pool_cleanup_null);
59 
60     *rwlock = new_rwlock;
61     return APR_SUCCESS;
62 }
63 
apr_thread_rwlock_rdlock(apr_thread_rwlock_t * rwlock)64 APR_DECLARE(apr_status_t) apr_thread_rwlock_rdlock(apr_thread_rwlock_t *rwlock)
65 {
66     apr_status_t stat;
67 
68     stat = pthread_rwlock_rdlock(&rwlock->rwlock);
69 #ifdef PTHREAD_SETS_ERRNO
70     if (stat) {
71         stat = errno;
72     }
73 #endif
74     return stat;
75 }
76 
apr_thread_rwlock_tryrdlock(apr_thread_rwlock_t * rwlock)77 APR_DECLARE(apr_status_t) apr_thread_rwlock_tryrdlock(apr_thread_rwlock_t *rwlock)
78 {
79     apr_status_t stat;
80 
81     stat = pthread_rwlock_tryrdlock(&rwlock->rwlock);
82 #ifdef PTHREAD_SETS_ERRNO
83     if (stat) {
84         stat = errno;
85     }
86 #endif
87     /* Normalize the return code. */
88     if (stat == EBUSY)
89         stat = APR_EBUSY;
90     return stat;
91 }
92 
apr_thread_rwlock_wrlock(apr_thread_rwlock_t * rwlock)93 APR_DECLARE(apr_status_t) apr_thread_rwlock_wrlock(apr_thread_rwlock_t *rwlock)
94 {
95     apr_status_t stat;
96 
97     stat = pthread_rwlock_wrlock(&rwlock->rwlock);
98 #ifdef PTHREAD_SETS_ERRNO
99     if (stat) {
100         stat = errno;
101     }
102 #endif
103     return stat;
104 }
105 
apr_thread_rwlock_trywrlock(apr_thread_rwlock_t * rwlock)106 APR_DECLARE(apr_status_t) apr_thread_rwlock_trywrlock(apr_thread_rwlock_t *rwlock)
107 {
108     apr_status_t stat;
109 
110     stat = pthread_rwlock_trywrlock(&rwlock->rwlock);
111 #ifdef PTHREAD_SETS_ERRNO
112     if (stat) {
113         stat = errno;
114     }
115 #endif
116     /* Normalize the return code. */
117     if (stat == EBUSY)
118         stat = APR_EBUSY;
119     return stat;
120 }
121 
apr_thread_rwlock_unlock(apr_thread_rwlock_t * rwlock)122 APR_DECLARE(apr_status_t) apr_thread_rwlock_unlock(apr_thread_rwlock_t *rwlock)
123 {
124     apr_status_t stat;
125 
126     stat = pthread_rwlock_unlock(&rwlock->rwlock);
127 #ifdef PTHREAD_SETS_ERRNO
128     if (stat) {
129         stat = errno;
130     }
131 #endif
132     return stat;
133 }
134 
apr_thread_rwlock_destroy(apr_thread_rwlock_t * rwlock)135 APR_DECLARE(apr_status_t) apr_thread_rwlock_destroy(apr_thread_rwlock_t *rwlock)
136 {
137     return apr_pool_cleanup_run(rwlock->pool, rwlock, thread_rwlock_cleanup);
138 }
139 
140 #else  /* HAVE_PTHREAD_RWLOCKS */
141 
apr_thread_rwlock_create(apr_thread_rwlock_t ** rwlock,apr_pool_t * pool)142 APR_DECLARE(apr_status_t) apr_thread_rwlock_create(apr_thread_rwlock_t **rwlock,
143                                                    apr_pool_t *pool)
144 {
145     return APR_ENOTIMPL;
146 }
147 
apr_thread_rwlock_rdlock(apr_thread_rwlock_t * rwlock)148 APR_DECLARE(apr_status_t) apr_thread_rwlock_rdlock(apr_thread_rwlock_t *rwlock)
149 {
150     return APR_ENOTIMPL;
151 }
152 
apr_thread_rwlock_tryrdlock(apr_thread_rwlock_t * rwlock)153 APR_DECLARE(apr_status_t) apr_thread_rwlock_tryrdlock(apr_thread_rwlock_t *rwlock)
154 {
155     return APR_ENOTIMPL;
156 }
157 
apr_thread_rwlock_wrlock(apr_thread_rwlock_t * rwlock)158 APR_DECLARE(apr_status_t) apr_thread_rwlock_wrlock(apr_thread_rwlock_t *rwlock)
159 {
160     return APR_ENOTIMPL;
161 }
162 
apr_thread_rwlock_trywrlock(apr_thread_rwlock_t * rwlock)163 APR_DECLARE(apr_status_t) apr_thread_rwlock_trywrlock(apr_thread_rwlock_t *rwlock)
164 {
165     return APR_ENOTIMPL;
166 }
167 
apr_thread_rwlock_unlock(apr_thread_rwlock_t * rwlock)168 APR_DECLARE(apr_status_t) apr_thread_rwlock_unlock(apr_thread_rwlock_t *rwlock)
169 {
170     return APR_ENOTIMPL;
171 }
172 
apr_thread_rwlock_destroy(apr_thread_rwlock_t * rwlock)173 APR_DECLARE(apr_status_t) apr_thread_rwlock_destroy(apr_thread_rwlock_t *rwlock)
174 {
175     return APR_ENOTIMPL;
176 }
177 
178 #endif /* HAVE_PTHREAD_RWLOCKS */
179 APR_POOL_IMPLEMENT_ACCESSOR(thread_rwlock)
180 
181 #endif /* APR_HAS_THREADS */
182